The Lord of the Rings, Appendix A, Annals of the Kings and Rulers: The Realms in Exile

With Tarannon, the twelfth king, began the line of the Ship-kings, who built navies and extended the sway of Gondor along the coasts west and south of the Mouths of Anduin. To commemorate his victories as Captain of the Hosts, Tarannon took the crown in the name of Falastur 'Lord of the Coasts'.

The Return of the King, LoTR Appendix A, Annals of the Kings and Rulers: Gondor and the Heirs of Anárion

[Owing] to the vigour of the 'Ship-kings', the line from Falastur onwards, Gondor reached the height of its power.

The Peoples of Middle-earth, HoME Vol 12, Part 1, Ch 7, The Heirs of Elendil: The Southern Line of Gondor: The Anárioni